Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x | /**
* @license Apache-2.0
*
* Copyright (c) 2025 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var normalizeIndex = require( '@stdlib/ndarray/base/normalize-index' );
var ndims = require( '@stdlib/ndarray/base/ndims' );
var sliceFrom = require( '@stdlib/ndarray/base/slice-from' );
var sliceTo = require( '@stdlib/ndarray/base/slice-to' );
var nulls = require( '@stdlib/array/base/nulls' );
var format = require( '@stdlib/string/format' );
// MAIN //
/**
* Returns an array containing a truncated view of an input ndarray and a view of the first element(s) along a specified dimension.
*
* @param {ndarray} x - input array
* @param {integer} dim - dimension along which to perform the operation
* @param {boolean} writable - boolean indicating whether returned arrays should be writable
* @throws {TypeError} first argument must be an ndarray having one or more dimensions
* @throws {RangeError} dimension index exceeds the number of dimensions
* @returns {Array<ndarray>} a list of ndarrays
*
* @example
* var ndarray = require( '@stdlib/ndarray/ctor' );
* var ndarray2array = require( '@stdlib/ndarray/to-array' );
*
* var buffer = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ];
* var shape = [ 3, 2 ];
* var strides = [ 2, 1 ];
* var offset = 0;
*
* var x = ndarray( 'generic', buffer, shape, strides, offset, 'row-major' );
* // returns <ndarray>
*
* var arr = ndarray2array( x );
* // returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]
*
* var y = shift( x, 0, false );
* // returns [ <ndarray>, <ndarray> ]
*
* arr = ndarray2array( y[ 0 ] );
* // returns [ [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]
*
* arr = ndarray2array( y[ 1 ] );
* // returns [ [ 1.0, 2.0 ] ]
*/
function shift( x, dim, writable ) {
var v0;
var v1;
var N;
var s;
// Retrieve array meta data:
N = ndims( x );
// Check whether we were provided a zero-dimensional array...
if ( N === 0 ) {
throw new TypeError( format( 'invalid argument. First argument must be an ndarray having one or more dimensions. Number of dimensions: %d.', N ) );
}
// Normalize the dimension index:
dim = normalizeIndex( dim, N-1 );
if ( dim === -1 ) {
throw new RangeError( format( 'invalid argument. Dimension index exceeds the number of dimensions. Number of dimensions: %d. Value: `%d`.', N, dim ) );
}
// Define a list of slice arguments:
s = nulls( N );
s[ dim ] = 1;
// Create a truncated view:
v0 = sliceFrom( x, s, false, writable );
// Create a view of the first element(s):
v1 = sliceTo( x, s, false, writable );
return [ v0, v1 ];
}
// EXPORTS //
module.exports = shift;
|